Field of the Invention
Embodiments of the present invention relate to the technical field of touch sensor for touch screen, and in particular to a touch sensor having a single ITO layer, a manufacturing method thereof and a touch screen having the same.
Description of the Related Art
In the prior art, a touch technology with a single layer of Indium Tin Oxide (abbreviated as ITO hereinafter) is widely used in the manufacturing touch screens due to several advantages such as low cost, capability of achieving multi-touch, and so on. So-called single ITO layer touch sensor refers to a touch sensor which is formed by plating an ITO layer onto a glass or plastic substrate and etching the ITO layer into electrodes. In such a touch sensor, the ITO electrodes may function not only as driving electrodes but also as sensing electrodes, facilitating a touch function without any other film layer.
However, on the one hand, since a refractive index of the ITO differs largely from that of the glass substrate (the refractive index of the ITO is on the order of 1.9-2.0, while the refractive index of the glass substrate is about 1.52), resulting in a significant difference in the reflectivity between an ITO area and an ITO-free area after circuits are formed by etching, and in turn highlighting the etched circuits so as to affect the visual feeling of its user. On the other hand, as far as a majority among all types of sensors used for touch screen, due to the existence of metallic layer, both sensor cutting marks and sensor binding regions are formed by etching the metallic layer and thus may be easily identified by CCD lens, i.e., there is no difficulty in alignment. However, as to a touch sensor with a single ITO layer, since there is no such metallic layer, both sensor cutting marks and sensor binding regions are formed by ITO and these cutting marks and binding regions subsequently become less apparent after ITO is processed by shadow elimination, such that these sensor cutting marks and sensor binding regions may not be identified by CCD lens during the cutting and the binding processes, resulting in that the individual sensors arranged on the glass substrate may not be cut and bound.
Therefore, as to a touch sensor with a single ITO layer, there is a problem to be solved for those skilled in the art, i.e., how to ensure that the sensor cutting marks and sensor binding regions may be easily identified when conducting shadow elimination thereon.